The present invention relates to periscope systems and more particularly to a novel periscope head assembly employing a plurality of self-contained, independently designed, reversible lens assemblies for providing a periscope system having a plurality of different selectable powers of magnification.
Periscope systems are presently in use, especially in submarines, for binocular viewing, stadimetric ranging, television camera viewing, photographing and radar surveillance. Periscopes are typically categorized as search periscopes and attack periscopes, the former typically being utilized for the search, target acquisition and navigational phases of operation while the latter are typically intended for use during the attack phase of operation.
Periscopes presently in use typically provided a capability of visual magnification selection between 1.5 and 6X. Modification kits have recently been developed to increase the capability to include 12X magnification for use in periscopes of both the search and attack type. However, the drive systems for selecting this particular power of magnification presently utilize torque motor driven cubes for shifting the power change lens assemblies creating the necessity for complicated electrical power means to effect shifts in the desired magnification.
In accordance with the present invention there is provided a head assembly for periscopes and the like, utilizing first and second Galilean telescope assemblies in conjunction with a lens assembly of the Petzval type, wherein both of the telescope assemblies are selectively and independently reversible to move to either of two operating positions through a 180.degree. rotation to permit simple and yet rapid selection of the desired magnification power. Having all of the optical elements functioning within the system under all magnifications leads to a system having a consistency of image quality previously unattainable.
Each of the lens assemblies is separately designed and bench adjusted to substantially eliminate the need for field adjustments and with a view toward significant size reduction so as to reduce the moment of inertia of the lens assemblies by a factor of 30 to 40 compared to conventional assemblies, thereby enabling magnification shifts to occur in 1/30th to 1/40th of the time required for conventional systems.
The mechanical drive system utilizes Geneva drive mechanisms which exert no deleterious influence on lens assembly locations, and hence upon optical collimation, and provide for sinusoidal motion of the reversible lens assemblies to prevent abrupt slamming of the lens assemblies into their location stops regardless of how quickly the assemblies are reversed.